Co-Authors:
Agassi, M., Dr. M. Agassi Soil Erosion Research Station Ruppin Institute Emek Hefer, 60960, Israel
Ben-Hur, M., Dr. M. Ben-Hur Agricultural Research Organization The Volcani Center Bet Dagan, 50 250, Israel
Abstract:
The approach in this study of runoff and erosion control on steep slopes was to combine soil stabilizers with the planting of drought-resistant, perennial plants. The effect of 10 t ha-1 phosphogypsum (PG) + 70 kg ha-1 polysaccharide (PS), 10 t ha-1 PG and 20 kg ha-1 polyacrylamide (PAM), and 200 kg ha-1 PS on the erosion of steep slopes (30-60%) was studied in plots 2 m in width and of different lengths (12-20 m), at three of different sites in Israel (semiarid conditions), and under natural rainfall conditions. Likewise, observations on the establishment and development of nonirrigated, drought-resistant, perennial plants on steep slopes (40-60%), combined with 10 t ha-1 PG + 70 kg ha-1 PS, were conducted at two sites in Israel. PS + PG and PAM + PG treatments were very efficient in erosion control in a wide range of soil types, ESP, CaCO3 level, and weather conditions. These treatments reduced erosion six- to eleven-fold in comparison with the control. No significant difference was found between PS + PG and PAM + PG treatments. However, the application of PAM was problematic due to its very low dissulution rate and its high viscosity in water. Two-hundred kg PS without PG was found efficient only at one experimental site with calcic haploxeralf soil and 300 mm average annual rainfall. The combination of PS + PG, and drought-resistant, perennial plants was very sucessful. The plants developed very well without irrigation throughout the long, dry summer. Only one year later, the creeper plant canopy covered an area of 0.75-1.5 m, and the bushes were 0.8-1.2 m in height. © 1992.